In recent years, sophisticated devices that are used while being worn on a body have been developed. Examples of the sophisticated devices include lifelogging devices for recording the amount of daily exercise, and smart devices which are spectacle-type or wristwatch-type information devices. For example, Japanese Unexamined Patent Application Publication No. 2013-146557 (PTL 1) describes a wristwatch-type wearable device. Such a sophisticated device uses an input button and a touch sensor formed by metal members.